re: Native American Flute

Really good looking flute.   Interesting build and how you came to do it.    
Old Osage friend played a flute.    Loved it.   
He had a "story" of how the Osage and other tribes got the hole down the center of the flute.   I think it was just a story to amuse and tease us kids.    Flute was made from a piece of wood with pith in the middle where the hole was to be.   As much as possible was dug out and then a wood eating worm was placed in the hole followed by a hot ember.   The worm would then chew to get away from the heat of the ember  The pith being softer was where the worm chewed.    Had to keep the worm and the ember apart but close enough that the worm chose to go with the pith and not out the side.  
Like the "story" but felt it was just that.   My old Osage friend never would admit it was just a myth.  
Your method has more favorable results.